Both the 450D and the 7D have excellent reputations as cameras, question is what are you looking for extra in a camera that the 450D isn't providing?

The 7D has the 'metal' body and weather sealing. Its a much bigger, heavier and more robust body with weather sealing too therefore fitting into the semi pro ranging. Heavier means more to lug around but some folks prefer the feel and balance of it.

Along with the more robust construction comes more pixels on the sensor and as it has 2 processors faster frames per second on continuous mode.

Because of its video capabilities it has also become a firm favorite amongst film makers on a budget.

There are a multitude of other 'upgrades' you'd get going from the 450D to the 7D.

I'd suggest that you might be worth attending the courses with your 450D and then buy the 7D afterwards if you feel the need.

There is also the strong argument that spending money on lenses is better spent than on camera bodies.

thanks ianganderton thats what im thinking about buying another body will cost me more. i recently bought tamron 17-50mm f/28..
i need to explore my 450d and attend more classes.
any idea what else to get for my 450d?

If video is the only benefit of the 7D over the 450D that you believe you'll make use of, it may perhaps not be worth the upgrade as there are bodies that can shoot 1080p video with a film like look for a lot less money (550D, 600D or the 60D) unless you prefer the ergonomics of the 7D.

I'm looking at upgrading to the 7D in a few months' time because of its faster continuous shooting rate, its autofocus points, its weather sealing and its balance with heavier lenses.

I'd have to disagree with Trevor as well. He's assuming that you learn better from reading online and most people know the maternal relationship of assumption. Everybody learns differently and a course or two may be beneficial.

Pretty much everything I know about using DSLRs comes from what I read online but I don't feel that spending money on a course is guaranteed to be a waste of my time.